Pros Aloft Without A Safety Line

[nautical62]

Originally Posted by skipmac

Another point, rock climbing your primary support is from your holds on the rock, the safety line is the backup. Mast climbing your primary support is not the mast but the lifting line so without a second line you have no backup.

True, but when ascending, and rappelling, climbers and cavers regularly commit to a single rope, same with rescues involving 3 people.

Personally, I’m not at all worried about a 10 mm or larger diameter halyard failing. It’s other components such as the pulley that worry me more.

[valhalla360]

Originally Posted by boatman61

This thread demonstrates the detrimental effects of banning kids from tree climbing..

Calculate the momentum and impact forces from a 50lb kid falling from a 20' high branch onto a grassy surface.

Now do the same calculation for a 150-200lb man falling from 40' up a mast onto a fiberglass deck with metal protrusions sticking up.

Even before you consider kids bones and ligaments tend to be more springy, you are looking at an order of magnitude lower likelihood of major injury due to a fall.

[boatman61]

And there was I thinking 50 or 200lbs it matters not as both achive an equal terminal velocity.. around 60mph if memory serves.. one of the reasons diving off a 10metre board is/can be painful to the head when you hit the water.
Theres also the fact that the poorer your climbing skills the greater the chance off falling.. thats also why folks often need to wear harnesses on deck.. poor balance/coordination from a life at a desk.
Abilities vary.. adapt to ones limitations or function to the limits of ones ability.. just dont see why I should be compelled to operate within your limitations..

[StuM]

Originally Posted by boatman61

And there was I thinking 50 or 200lbs it matters not as both achive an equal terminal velocity.. around 60mph if memory serves.. one of the reasons diving off a 10metre board is/can be painful to the head when you hit the water.

Diving off a 10m board, you will reach about 35mph by the time you hit the water.

From 25m, it's about 60mph

A belly down skydiver will reach a terminal velocity of about 120 mph, but because air resistance increases the faster (s)he is falling, it takes about 12 seconds to reach that speed and (s)he will fall about 400m in that time.

(mixed imperial and metric units to stay in sync with the original post )

[double u]

V = squarerrot of 2gh...

[double u]

imho the big jump in risk is, if you can't climb on your own but have to be winched...

[valhalla360]

Originally Posted by boatman61

And there was I thinking 50 or 200lbs it matters not as both achive an equal terminal velocity.. around 60mph if memory serves.. one of the reasons diving off a 10metre board is/can be painful to the head when you hit the water.
Theres also the fact that the poorer your climbing skills the greater the chance off falling.. thats also why folks often need to wear harnesses on deck.. poor balance/coordination from a life at a desk.
Abilities vary.. adapt to ones limitations or function to the limits of ones ability.. just dont see why I should be compelled to operate within your limitations..

In a fall from 20-40', you won't reach terminal velocity (it's roughly double your 60mph assumption though).

Also, while it will have negligible impact on this analysis as you will hit the ground before air drag has a significant impact, terminal velocity for an adult will typically be greater than for a child. Terminal velocity is a function of weight to drag. As you increase the size of a person, typically, the weight goes up faster than the surface area. The greater the weight to drag ratio the higher the terminal velocity. (this of course assume both are in a similar position)

Even if you assume the same velocity on impact, the adult will have a much tougher time surviving the uninjured due to the greater forces applied. The forces increase at a greater rate than the the structure of the body's ability to absorb them increases. This is why small animals, like squirrels can fall from amazing heights without injury but a large animal like a cow, will likely be killed or seriously injured from even a 5-10 fall.

And this still ignores that under trees is typically a grassy area that has some give to absorb the impact but under masts, it typically hard fiberglass deck with metal protrusions that don't have a lot of give.

Once you are falling, your greater climbing skill doesn't make the landing any softer. Someone working as a professional may have 1/10th the chance of making a mistake (not buying it but for arguments sake) but if they go up a mast 100 times more often, they have 10 times greater chance of having a fall. Of course, I'm not buying the idea the "pro" is less likely to fall. The guy who goes up the mast once a year, is likely double checking the harness and if it's windy or wet, they hold off for a better day...the "pro" goes up no matter what often without double checking because..."they've done it a thousand times".

I would be curious to see if these "pros" carry insurance and what the insurance tells them if they say they don't use a safety line.

[boatman61]

Originally Posted by double u

imho the big jump in risk is, if you can't climb on your own but have to be winched...

Agreed... need a lot of faith in the person operating the winch.. having flown off the deck a couple of times in the past hauling down a spinny sock in winds when the feeder screwed up its a faith I am short on.
My younger days mast climbing.. also going up a furled foresail works really well as DoubleU has stated.

[double u]

...if someone does not have the strength to hold on & safely climb down the furled genoa, thats when valhalla looms...!
I've seen them sitting in the b-chair like sacks of grain, 2 people sweating on the winch - that are the big-risk-takers!

[boatman61]

Originally Posted by valhalla360

In a fall from 20-40', you won't reach terminal velocity (it's roughly double your 60mph assumption though).

Also, while it will have negligible impact on this analysis as you will hit the ground before air drag has a significant impact, terminal velocity for an adult will typically be greater than for a child. Terminal velocity is a function of weight to drag. As you increase the size of a person, typically, the weight goes up faster than the surface area. The greater the weight to drag ratio the higher the terminal velocity. (this of course assume both are in a similar position)

Even if you assume the same velocity on impact, the adult will have a much tougher time surviving the uninjured due to the greater forces applied. The forces increase at a greater rate than the the structure of the body's ability to absorb them increases. This is why small animals, like squirrels can fall from amazing heights without injury but a large animal like a cow, will likely be killed or seriously injured from even a 5-10 fall.

And this still ignores that under trees is typically a grassy area that has some give to absorb the impact but under masts, it typically hard fiberglass deck with metal protrusions that don't have a lot of give.

Once you are falling, your greater climbing skill doesn't make the landing any softer. Someone working as a professional may have 1/10th the chance of making a mistake (not buying it but for arguments sake) but if they go up a mast 100 times more often, they have 10 times greater chance of having a fall. Of course, I'm not buying the idea the "pro" is less likely to fall. The guy who goes up the mast once a year, is likely double checking the harness and if it's windy or wet, they hold off for a better day...the "pro" goes up no matter what often without double checking because..."they've done it a thousand times".

I would be curious to see if these "pros" carry insurance and what the insurance tells them if they say they don't use a safety line.

Winding you up mate.. each to their own..

[double u]

methinks a discussion of the results of a fall is completely beside the point (& they will be grave, very grave if not fatal): we MUST NOT FALL! period! there is no room for error, none! for me concentration, focus & fitness always did it. (but maybe that comes from successfully blue-watering a wharram cat, eh BM61?)

[rabbi]

Originally Posted by boatman61

This thread demonstrates the detrimental effects of banning kids from tree climbing..

My kids just go up the shrouds. Initially they got up there quicker than I could stop them, and now I just accept that they do it when they feel like. Rule is not to go any higher than the spreaders.


Getting myself up there is different story.
Two ascenders to get me up, plus a wife on a safety line.
For short jobs I use a rock climbing harness. For jobs that take longer I add a bosuns chair for comfort, but I prefer to trust my life to the climbing harness.